Resonant capacitor bank in medium-frequency induction heating furnace

Here we are introducing one of our special power capacitor banks which used in medium-frequency induction heating furnace. By choosing suitable capacitor banks for your induction heating system may saving up 38% energy and improving induction heating performance up 22%. 

So to be a crucial components in medium-frequency induction heating furnace, what is the core function of capacitor banks? 

1.Resonant circuit formation: It will connect with the induction coil to create resonance, maximizing current amplitude in the coil for intense magnetic fields and effectively heating. 

2.Reactive power compensation: Provide with reactive power to support the inductive coil and whole induction heating power system, so as to improve overall power factor and tune circuit.

There are solid medium, liquid medium for options, air-cooled, water-cooled for options; 

Higher frequency Higher Voltage level like 500Hz~300kHz is applicable of liquid medium with internal water-cooling heat dissipation design. 

Lower frequency Lower voltage like 50hz~300Hz is applicable of solid/liquid medium with air-cooling design. 

But it is not absolute design capacitor in this way. We have many design with frequency up to 10khz water-cooled capacitors, and 5khz air-cooled capacitors as well. The induction heating capacitor bank design mostly depends on the medium-frequency design and structure, such as frequency 500hz~300khz, voltage level, IGBT based or thyristor-based MF power supplies, cooling method, series or parallel resonance circuit, work-piece properties. The work-piece properties will affect a lot for whole induction heating system design. 

Here is reference about recommended frequency ranges: ​

1.Parallel Resonant Circuits: The capacitor bank is connected in parallel with the induction coil, common in traditional thyristor-based MF power supplies.

2.Series Resonant Circuits: The capacitor bank is connected in series with the load, a more modern, efficient design that allows for higher power factors and easier control

Voltage level (AC or DC)?

Rating Current? 

Frequency? 

Output Power/capacitance value: kVar/microfarad ?

1) Individual Test Certificate: Each unit must come with a test report of withstand voltage and actual capacitance/voltage/current measurement, leak test etc.  

2) Connection Compatibility: specify the terminal threads and the cooling water inlet/outlet threads.

3) Capacitor manufactured according to IEC 60110-1 (specific to induction furnace capacitors). 

4) Dielectric: Polypropylene film (PCB-free), All-film structure, good for harsh working environment. 

5) Case Material: Aluminum alloy (Non-Magnetic)

6) Losses (W/kvar): Lowest possible value (e.g., < 0.5 W/kvar)

7) Third-Party Inspection available